In many food preparation facilities, such as commercial kitchens and restaurants, the sink is a major source of various types of food waste. In the course of normal operation, liquid food wastes containing FOG are inadvertently or intentionally introduced to the drainage system and, in other cases, a mechanical chopper such as a garborator is used to shred the food waste as it leaves the sink and enters the wastewater system. Many food preparation establishments, such as commercial restaurants and the like, have multiple sinks for such food waste disposal.
In the majority of jurisdictions, the disposal from commercial kitchens of FOG and FOG laden debris into the sanitary sewage system is prohibited. There are a number of reasons why this is so, including the ability of those types of materials to clog or plug sanitary sewage systems and the difficulty of adequately treating such materials in a sewage treatment facility. Therefore, many jurisdictions require that these materials be removed from the wastewater stream before permitting the wastewater stream to be added to the sanitary sewer system.
As a result, devices known as grease interceptors have been developed. These grease interceptors are connected to the wastewater effluent stream from the food preparation kitchen or other facility and are integrated with the building drain before entering the municipal system. The interceptor may commonly be located internally within the kitchen or externally adjacent to the building. The grease interceptors may take a number of forms, but typically consist of an in-line container which is mounted on, at or below grade within the wastewater discharge system downstream of all of the discharging appliances and the like. The container includes features that are configured to allow fats, oils and grease to float to the surface of the container where they can be physically or mechanically removed for controlled disposal. In this way these wastes are removed from the wastewater before the wastewater enters the sanitary sewer system.
Some examples of grease interceptors include the following:
U.S. Pat. No. 2,003,140 issued May 28, 1935;
U.S. Pat. No. 2,414,949 issued Jan. 28, 1947;
U.S. Pat. No. 5,271,853 issued Dec. 21, 1993;
U.S. Pat. No. 5,505,860 issued Apr. 9, 1996;
U.S. Pat. No. 5,714,069 issued Feb. 3, 1998;
U.S. Pat. No. 6,951,615 issued Oct. 4, 2005;
U.S. Pat. No. 7,296,694 issued Nov. 20, 2007;
U.S. Pat. No. 7,300,588 issued Nov. 27, 2007;
U.S. Pat. No. 7,427,356 issued Sep. 23, 2008;
U.S. Pat. No. 7,452,472 issued Nov. 18, 2008;
U.S. Pat. No. 7,481,321 issued Jan. 27, 2009;
Canadian Patent No. 2,299,134 issued Sep. 1, 2009;
Canadian Patent No. 2,672,865 issued Jul. 31, 2012; and
Canadian Patent Application No. 2,769,800, published Aug. 28, 2013.
While these different inventions all have various features and benefits, consistent challenges facing these interceptors, particularly for larger interceptors, include: efficiently separating FOG from wastewater, controlling the rate of flow into the tank and clearing blockages within the system. Some more developed solutions employ flow control devices to manage the flow rate of fluid entering the interceptors, but those devices are often at risk of being blocked by foreign object debris. Removable baffles have been used to attempt to allow cleaning within an interceptor, but these prior art removable baffles often do not provide access to fluid channels within inlet assemblies which may contain blockages. In addition, these prior art removable baffles are not always accessible or are obstructed by external objects or elements within the operational environment. What is desired is a way to control the flow rate and type of flow of fluid through a grease interceptor to effectively separate FOG from wastewater without excessively turbulent flow. What is also desired is a way to provide for the separation of FOG using a grease interceptor within which key functional elements can be cleaned, accessed and unblocked more easily.